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of both saturated and unsaturated fats be reduced in the average U.S.
diet. An appropriate and practical target is to reduce the intake of
fat from its present level (approximately 40%) to 30% of total calo-
ries in the diet. The scientific data do not provide a strong basis
for establishing fat intake at precisely 30% of total calories. Indeed,
the data could be used to justify an even greater reduction. However,
in the judgment of the committee, the suggested reduction (i.e., one-
quarter of the fat Intake) is a moderate and practical target, and is
likely to be beneficial.

2. The committee emphasizes the importance of including fruits,
vegetables, and whole grain cereal products in the dally diet. In
epidemiological studies, frequent consumption of these foods has been
inversely correlated with the incidence of various cancers. Results
of laboratory experiments have supported these findings in tests of
individual nutritive and nonnutritive constituents of fruits (especially
citrus fruits) and vegetables (especially carotene-rich and cruciferous
vegetables).

These recommendations apply only to foods as sources of nutrients—
not to dietary supplements of individual nutrients. The vast litera-
ture examined In this report focuses on the relationship between the
consumption of foods and the Incidence of cancer in human populations.
In contrast, there is very little information on the effects of various
levels of individual nutrients on the risk of cancer in humans. There-
fore, the committee Is unable to predict the health effects of high and
potentially toxic doses of Isolated nutrients consumed in the form of
supplements.

3. In some parts of the world, especially China, Japan, and Ice-
land, populations that frequently consume salt-cured (Including salt-
pickled) or smoked foods have a greater incidence of cancers at some
sites, especially the esophagus and the stomach. In addition, some
methods of smoking and pickling foods seem to produce higher levels of
polycyclic aromatic hydrocarbons and N-nitroso compounds. These com-
pounds cause mutations in bacteria aricf cancer In animals, and are sus-
pected of being carcinogenic in humans. Therefore, the committee recom-
mends that the consumption of food preserved by salt-curing (including
salt-pickling) or smoking be minimized.

4. Certain nonnutritive constituents of foods, whether naturally
occurring or Introduced Inadvertently (as contaminants) during pro-
duction, processing, and storage, pose a potential risk of cancer to
humans. The committee recommends that efforts continue to be made to
minimize contamination of foods with carcinogens from any source. Where
such contaminants are unavoidable, permissible levels should continue to
be established and the food supply monitored to assure that such levels
are not exceeded. Furthermore, intentional additives (direct and Indi-
rect) should continue to be evaluated for carcinogenic activity before
they are approved for use In the food supply.